X-ray powder diffraction data for ErH(2-x)Dx...

We report X-ray powder diffraction data for ErH2-xD�x formed by hydrogen (i.e. protium)-deuterium loading of Er metal. Lattice parameters for the varying hydrogen-deuterium compositions followed Vergard's law behavior. The cubic lattice parameter at room temperature for ErH2-xD�x obeys a linear relationship according to the formula a = 5.1287 -1.1120�10-4�x; where a = the lattice parameter of the fluorite-type structure and x = the mole percent of deuterium. Microstrain measurements suggest a possible ordering of hydrogen and deuterium in the composition ErH1D1.